Paint remover



Patented Apr. 10, 1951 Wynkoop, Brooklyn, N. Y., assignors toTurco Products, Inc, Los Angele's, Califl, a .eiiipoi'a tion of California No Drawing. Original application Aprilr20, 19.45, Serial No. 585M156, now Patent No. 2,115,113, dated June 15, 1948. Divided and this application June 30, 1947, Serial No. 758,236

11 Claims.- 1 v This application is a division of application Serial No. 589,456,-fi1ed April- 2051945, new Pat ent No. 2,443,173, issued June 15, 1948.

This invention relates to a paint, varnish, lacquer, and enamel remover.

Protective coatings, e.'g'., paints, varnishes, and lacquers, are composed of a pigment dispersed in a vehicle which has the property of forming a tough film onthe surface coated thereby. Such protective coatings may be ofthe drying-oil type, employing tuiig oil,-linseed oil, oiticica oil; or fish oils. They may be formed of rosin, polymerized rosi'n,or synthetic ester-gums, for example, glycerol triabietate or pentaerythritol tetraabietate', maleic-modified ester gum, phenolic-modified ester gum, phenolic resins, urea resins, melamine resins, alkyd resins, etc.

The necessity for removing such, and other commonly employed, protective coatings has resulted in the development of what is generally referred to as paint removers. Prior art paint removers include the alkali type, which includes aqueous mixtures containing alkali or ammonia diss'olvedtherein. They may be classed as aqueous in the sense that water forms the major proportion 'of the constituents employed and water or water solution forms the external or continuous phase. Such materials act primarily by chemical attack on the protective coating film.

. We have'developeda paint remover of the non aqueous type,- employing this term in the sense that the continuous or external phase is an organic solvent for the paint, varnish, lacquer, or enamel film. This organic solvent may contain some water in solution or emulsion. Water, if

present, forms but arelatively minor proportion of the constituents of the formulation, ranging from less than 1% to about 20% by weight. The

composition has dispersed therein a colloid which imparts thixotropic properties to the organic liquid. The dispersion also has a high adhesive tension against the protective coating.

Because of these properties the paint remover of our invention can be sprayed, brushed, or run into a surface coated by the protective coating to be removed. The thixotropic gel characteristics of the composition forming the paint remover of our invention are such that the mechanical motion'inher'ent in the application of the paint re mover to the coated surface gives a liquid of such low viscosity as to permit ready application.

When applied to the surf-ace to be treated, the gel is re-established and a relatively thick coat of the composition adheres to the protective coating. is equally sobotlr for horizontal and vertical surfaces. The'coating of the thixc'tropic composition will not run appreciably on vertica-l ror horizontal'surface but will remaini-h place where applied after the mechanical agitation incidental to application is discontinued;

We'may therefore place a: thick coat of paint remover on the surface to be treated withmi m- 1hurri-ruii-off and with no-ru-n' -ofi; if care is" takenin its applicati The coating of the re mover may tie-readilyremoved by wiping its gel properties being destroyed by the mechanical agitation due to wiping: Itma'y also be removed by washing with water, the mechanical agitation in this case also being assisted by the emulsifica' tion or dispersion-of the' p'ai-nt remover in the Water due to thepresenc'e of emulsifying or dis persing agents in our paint remover;

We employas our active paint remover solvent a chlorinated organic solvent. Such ma terials include, for example, methylene chloride;- ethylene chloride, .trichloroethylene; perchlor' ethylene, dichloroethylene ether, dichloriscpropyl ether, monochlor benzene, and. dichlorobenzene. These are listed to illustrate the nature of the solvents employed and are not intended to limit the scope of the disclosed invention to such listed compounds. All of these compounds are solvents for protective films such as described above; We may employ other organic paint film solventswhich have the propertiesspecified above, We prefer to' use the chlorinated organic solvents, since they have particularly good paint-removing action andiormth'ethixotropic material of our invention readily and act in such mixture, .in' combination with the other ingredients thereof,

in a highly efiicacious manner... 7 V

In order to impart thixotropi'c properties to such: chlorinated solvents,- we disperse therein-a protein colloid suchas casein,'ze'in', protein material derived tram" seyaibean meal or cottonseed meal or rnixtures thereoii V In* order to assist? inthe dispersion ofs'aidcdh" loid and impart emui'sirying characteristics a our paint remover,"we" may employ a soapj-su'ch" asthealkalimetai or aifim'onia seap's-of the fatty or unsa-mratee-raay acids, for example: the soaps o fpal c, stearidoleic; ricinoleielinoleic acid, thecor espendingsoaips of the resin acids, such as the? abieta-tes or' the impure aliietates known as"talloil 7 We also employ as suseiemehary" dispersing agents-inadditien a tli tote-steps: the sa'lts of the phenols, includi 1114 the *termhenol CsI-IsOI-I, as well as the 'substituted phencls such" 3 as the cresols or cresylic acids, for example, the petroleum cresylic acids.

The soap and phenolic salts are preferably formed by reacting the carboxylic acid and the phenol with NaOH, KOH, or NH4OH. We may employ the base in amount equivalent to a portion or all of the carboxylic acid, and may also, if desired, employ the base in amount equivalent to a portion of the phenol but insufficient to neutralize both the acid and the phenol.

.While we do not desire to be bound by any theory of the reactions which occur, we believe that the active dispersing ingredient includes the soap of the acid and some phenolate or cresylate, but that a portion of the phenol, for example, cresol, is in its acid form; in other words, we have an excess of phenol, for example, cresol, in our composition.

We form the thixotropic dispersion of the protein in the chlorinated solvent with the aid of such dispersing agents. The dispersion may be assisted by the use of mutual solvents. These mutual solvents may also act to reinforce the solvent action of the chlorinated solvent to improve the paint-removing properties of the resultant formulation. Such modifying solvent is preferably an alcohol and includes the monohydric and polyhydric alcohols. We find the lower aliphatic alcohols, such as methyl, ethyl, or propyl alcohol, or isopropyl alcohol, particularly useful for such purpose.

We may employ such mutual solvents as the monohydric alcohols, such as methyl alcohol, ethyl alcohol, propyl alcohol, or isopropyl alcohol, or the polyhydric alcohols, such as glycol or glycerine or their monoalkyl ethers, for example, ethylene glycol, propylene glycol, diethylene glycol, hexane-L2 diol, the glycol ethers, such as ethyleneglycolmonoethylether, ethyleneglycolmonomethylether, ethyleneglycolmonopropyl ether, diethyleneglycol, polyethyleneglycol, or

. glycerine.

These solvents not only act as solvent modifiers to develop the thixotropic properties of the protein dispersion but also have the property of adding to or reinforcing the paint-removing solvent properties of the chlorinated solvent. This is particularly true. of the monohydric alcohols or the lower aliphatic alcohols such as the methyl, ethyl or propyl or isopropyl alcohol. We may therefore employ such lower aliphatic alcohols as additives to the polyhydri alcohols or their ethers to supply not only the desired mutual solvency action but the desirable reinforcement of thepaint-removing solvent action of the chlorinated solvent.

The free cresol or phenol also has a solvency action, both as a mutual solvent and as an agent to reinforce the action of the paint-removing solvent upon the protective coating.

We have found that, although not essential to the utility of Our paint remover, a small amount of wax, such as a petroleum wax, for example, one having a melting point of about 125 F. to 135 F., improves the efficiency of the paint remover by retarding the evaporation of the solvent while in contact with the coated surface.

The compositions thus formed contain the chlorinated solvent in preponderate amount, being one of the components of the mixture present in greatest quantity. The organic liquid component, i. e., chlorinated solvent, other mutual solvent, and amines when employed forms the major component of the composition, the casein, soap,

and phenol, when employed, forming the com ponents used in minor amounts. The casein and the soap, phenol, mutual solvent or amine are added in amounts to establish the desired thixotropic dispersion of the casein in the chlorinated solvent to form a. uniform dispersion of the ingredients in the organic liquids of the composition.

The paint remover thus formed has the thixotropic properties previously referred to. Additionally, it is quite readily emulsified or dispersed in water so that it can be readily washed off from the painted surface to leave a clean surface free of the protective film and free of the paint remover.

We have found that the formulation of the paint remover according to our invention is improved by the use of an amine. We have found that the protein is effectively dispersed in the organic paint-removing solvent by the use of such amine. The resultant paint remover has the thixotropic properties previously referred to.

The amines which may be employed in making our thixotropic paint remover include the aliphatic amines, cyclo aliphatic amines, aryl aliphatic amines, aromatic amines, hydroxy aliphatic amines, or commercially available mixtures of such amines. Among such compounds may be mentioned, for example, monoethanolamine, diethanolamine, triethanolamine, andmixtures thereof, including such as occur in commercial triethanolamine, morpholine, propanolamines, including normal propanolamine and triisopropanolamine, butanolamines, pentanolamines, hexanolamines, glycerolamines; alklyol-- polyamines, such as alkylol derivatives of ethylendiamine and diethlenetetramine; alkylated and other derivatives of alkylolamines, including for example, diethylaminoethanol, phenylethanolamine, phenyl diethanolamine, cyclohexylethanolamine, phenylmorpholine, monomethylethanolamine, dimethylethanolamine, monoethyltriethanolamine, diethyltriethanolamine, ethylphenylethanolamine, and the like; alkylamines, such as ethylenediamine, diethylenetriamine, triethylenetetramine, butylamine,-

hexylamine, octylamine, laurylamine, mono- :methylethylenediamine, monoethyldiethylenetriamine, l,l-dimethylethylenediamine, and the like; and aromatic and heterocyclic bases, such as pyridine, benzylamine and homologues there,- of, and derivatives or substitution products thereof.

The following examples illustrate the formulations embodying the principles of our invention:

Example 1 We heat grams of triethanolamine and 25 grams of casein at an elevated temperature for several hours until a smooth dispersion has been formed. After cooling, we then add 30 cc. of ethanol (95%) and finally add cc. of ethylenedichloride in which 2 grams of parafin have been dissolved. In this case we omit the soap and cresylic acid and prolong the heating for a sufficient period to obtain the necessary dispersion of the casein.

We have found, however, that th dispersion of the casein on the organic solvent is assisted by the use of a mutual solvent such as those listed above. Such formulations'are exemplified below.

Example 2 We mix 60 grams of diethyleneglycol, 20 grams of cyclohexylamine, and 35 grams of casein, and

heat the mixture until formed. We then add grams of ethanol (95%), adding the .ethanol slowly to avoid curdling and add 120 grams of ethylene dichloride in which we have dissolved 3 grams of parafiin wax.

The formulations employing amines as dispersing agents are further improved by adding soaps such as previously described. or the salts of the phenols or cresols described above. dispersing agents also improve the. dispersibility of the formulated paint remover in water. The formulations thus produced have excellent thixotropic properties and will form thick coatings which adhere to surfaces and may be readily removed by wiping or washing with water.

Example 3 We disperse grams of casein in 20 grams of cyclohexylamine and 50 grams of diethyleneglycol. To this mixture we add a second mixture formed by reacting 2.7 grams of 50% KOH With 7.6 grams of oleic acid, 23.45 grams of cresol, and 2.5 grams of water. We then add 35 ml. of 95% ethanol, and finally add 120 grams of ethylene dichloride in which we have dissolved 3 grams of parafiin.

Example 4 We disperse grams of casein in 25 grams of diethylene glycol and 20 grams of triethanolamine. We then add a mixture formed by reacting 33.5 grams of cresol, 4 grams of water and 3.8 grams of KOH and 10.8 grams of oleic acid. We then add 40 ml. of ethanol and then add a solution of 80, ml. ethylene dichloride and 40 ml. of dichloroisopropylether in which we have dissolved 2 grams of paraflin.

Example 6 We disperse 40 grams of casein in 25 grams of diethylene glycol and 20 grams of pyridine. To this dispersion we add a mixture formed by reacting 21.6 grams of oleic acid, 6.7 grams of cresol and 7.6 grams of 50% KOH and 8. grams of water. We then add 30 cc. of 95% ethanol. We then add ccpof ethylene dichloride inwhich we have dispersed 2 grams of paraffin wax.

Example 7 We disperse 30 grams of casein in 25 grains of diethylene glycol and 15 grams of aniline. To this dispersion we add a mixture formed by re. acting 10.8 grams of oleic acid,.33.5 grams of cresol and 3.8 grams of 50% KOl-I and i grams of water. We then add 30 ml. of ethanol and a mixture of 50. cc. ethylene dichloride and. '75

cc. of monochlorobenzene. in which we have dissolved 3 grams of parafiin.

In forming our paint remover in accordance with these formulations, we heat the protein, amine, and the polyhydric compound to a tem:'

perature of about F. to 200,F. until a smooth. dispersion of the protein in the amine, and poly-.

a smooth dispersion is To this mixture we add a mixture.

These 6. hydroxy compound is formed. A solution of .al kali, oleic acid, cresol, or phenol, containing some Water, is formed. This solution is acidic, being of a pH in the neighborhood of 5 to 6. It is added to the hot dispersion of the protein and the mixmay react with the soa or compete with the oleic acid for the base so that a distribution of the base between the phenol or cresol and the carboxylic acid may occur. When we refer to a paint remover comprising a soap and a phenol, for

. example, cresol, we mean to include also such composition containing the carboxylic acid of said soap and the salts of said phenol.

While We have employed in all of theabove examples insufficient alkali to convert the cresols into the salt, and thus the cresol is probably added as free cresol, We do not exclude the possibility of some interaction between the amine and the cresol when they are compounded. Therefore, wherein we refer to a paint remover containing a phenol or cresol and an amine, we mean to include the products of interaction between the cresol and the amine.

In formulating our paint remover we employ sufficient protein colloid and-dispersing agent to form a thixotropic dispersion of the protein colloid in said solvent. The proportions of protein colloid, dispersing agent, amine, when employed, mutual solvent, and alcohol are adjusted to give such thixotropic dispersion. The exact proportions may be adjusted over a wide range, depending on the materials employed as protein colloid, paint removing solvent, and mutual solvent and dispersing agent. However, for. any particular formulation, the relative proportions of .1 the protein colloid, dispersing agent, and mutual solvent which will yield a thixotropic dispersion in accordance with our invention are adjustable over relatively narrow limits. These limits, how:

ever, will vary somewhat with the character of these materials employed and the relative proportions of the components of the particular formulation.

While we have described a particular embodiment of our invention, it should, be understood. that various modifications and adaptations therean organic amine, said dispersion of, the protein being in a mixture of a liquid chlorinated hydroearbon solvent and mutual solvent modifier.

taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said liquid chlorinated:- hydrocarbon solvent being in preponderate proportion, and said water being in the range of about 1% to about 20% by weight of said thixotropic paint remover, and said dispersion being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the: property of adhering to painted surfaces without sub-: stantial running and dispersible in water ,soethat itm'ay be washed from a surface to which it is applied.

2. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a protein colloid in a paint remover solvent and including an organic amine and the reaction product of an organic amine with an organic acid taken from the roup consisting of the soap-forming saturated fatty acids, soap-forming unsaturated fatty acids, and resin acids, said dispersion of the protein being in a mixture of a liquid chlorinated hydrocarbon solvent and mutual solvent modifier taken from the group of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said liquid chlorinated hydrocarbon solvent being in preponderate proportion, and said water being in the range of about 1% to about 20% by weight of said thixotropic paint remover, and said dispersion being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

3. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a protein colloid in a paint remover solvent and including an organic amine and the reaction product of an organic amine with a phenol and also with a soap-forming organic acid taken from the group consisting of the soap-forming satu-- rated fatty acids, soap-forming unsaturated fatty acids and resin acids, said paint remover solvent being composed of a liquid chlorinated hydrocarbon solvent and a mutual solvent modifier taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said water being within the range of about 1% to about 20% by weight of said thixotropic paint remover, said liquid hydrocarbon solvent being the predominating ingredient, and said paint remover being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

4. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a protein colloid in a paint remover solvent and in cluding an organic amine, said paint remover solvent being composed of a liquid chlorinated hydrocarbon solvent in preponderate proportion and a mutual solvent modifier taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said water being within the range of about 1% to about 20% by Weight of said thixotropic paint remover, said organic amine being in the range of from 4% to by weight of said thixotropic paint remover, and said paint remover being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces Without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

5, A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a casein colloid in a paint remover solvent and including an organic amine, said dispersion of the casein being in a mixture of a liquid chlorinated hydrocarbon solvent and mutual solvent modifle'rtaken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said chlorinated hydrocarbon solvent being in preponderate proportion, and said water being in the range of about 1% to about 20% by Weight of said thixotropic paint remover, and said dispersion being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

6. A thixotropic Water dispersible paint remover, comprising a thixotropic dispersion of a casein colloid in a paint remover solvent and including an organic amine and the reaction product of an organic amine with an organic acid taken from the group of the soap-forming saturated fatty acids, soap-forming unsaturated fatty acids, and resin acids, said dispersion of the casein being in a mixture of a liquid chlorinated hydrocarbon solvent and mutual solvent modifier taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said chlorinated hydrocarbon solvent being in preponderate proportion, and said water being in the range of about 1% to about 20% by weight of said thixotropic paint remover, and said dispersion being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in Water so that it may be washed from a surface to which it is applied.

7. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a casein colloid in a paint remover solvent, a casein colloid dispersent comprising an organic amine and the reaction product of an organic amine with a phenol and also with a soap-forming organic acid taken from the group consisting of the saturated fatty acids, unsaturated fatty acids and resin acids, said paint remover solvent being composed of a liquid chlorinated hydrocarbon and a mutual solvent modifier taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said water being within the range of about 1% to about 20% by weight of said thixotropic paint remover and said liquid chlorinated hydrocarbon solvent being in preponderate proportion, and said paint remover being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of ad boring to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

8. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a casein colloid in a paint remover solvent, and an organic amine, said paint remover solvent being composed of a liquid chlorinated hydrocarbon and a mutual solvent modifier taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said water being within the range of about 1% to about 20% by weight, said organic amine being in the range of from 4% to 10% by weight of said thixotropic paint remover, and said liquid chlorinated hydrocarbon solvent being in preponderate proportion and said paint remover being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

9. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a protein colloid in a paint remover solvent and including an organic amine and the reaction product of an organic amine with a phenol, said pain remover solvent being composed of a liquid chlorinated hydrocarbon solvent and a mutual solvent modifier taken from the group of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said water being within the range of about 1% to about 20% by weight of said thixotropic paint remover, said liquid hydrocarbon solvent being the predominating ingredient, and said paint remover being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

10. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a casein colloid in a paint remover solvent, at casein colloid dispersent comprising an organic amine and the reaction product of an organic amine with a phenol, said paint remover solvent being composed of a liquid chlorinated hydrocarbon and a mutual solvent modifier taken from the group of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent, said water being within the range of about 1% to about 20% by weight of said thiXotropic paint remover and said liquid chlorinated hydrocarbon solvent being in preponderate proportion, and said paint remover being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dis persible in water so that it may be washed from a surface to which it is applied.

11. A thixotropic water dispersible paint remover, comprising a thixotropic dispersion of a protein colloid in a paint remover solvent, said dispersion of the protein being in a mixture of a liquid chlorinated hydrocarbon solvent and a mu tual solvent modifier taken from the group consisting of the aliphatic alcohols and aliphatic ether alcohols and water dispersed in said solvent,

and cointaining also a dispersing agent chosen from the group consisting of the organic amines and the reaction products of organic amines and acidic components, said acidic components being chosen from the group consisting of the soap forming saturated fatty acids, the soap forming unsaturated fatty acids, resin acids, and phenols, and said liquid chlorinated hydrocarbon solvent being in preponderate proportion, and said water being in the range of about 1% to about 20% by weight of said thixotropic paint remover, and said dispersion being thixotropic so that on agitation said mixture is a fluid and when at rest is a gel having the property of adhering to painted surfaces without substantial running and dispersible in water so that it may be washed from a surface to which it is applied.

NATHANIEL L. BAUM.

JEAN WYNKOOP.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,113,971 Ellis Oct. 20, 1914 1,474,984 Van Ness Nov. 20, 1923 2,398,242 Morgan et al Apr. 9, 1946 2,443,173 Baum et a1 June 15, 1948 FOREIGN PATENTS Number Country Date 357,128 Great Britain Sept. 7, 1931 OTHER REFERENCES Uses and Applications of Chemicals and Re lated Materials, Gregory, Reinhold Pub. Corp., N. Y. C., 1939, page 157. 

1. A THIXOTROPIC WATER DISPERSIBLE PAINT REMOVER, COMPRISING A THIXOTROPIC DISPERSION OF A PROTEIN COLLOID IN A PAINT REMOVER SOLVENT, AND AN ORGANIC AMINE, SAID DISPERSION IF THE PROTEIN BEING IN A MIXTURE OF A LIQUID CHLORINATED HYDROCARBON SOLVENT AND MUTUAL SOLVENT MODIFIER TAKEN FROM THE GROUP CONSISTING OF THE ALIPHATIC ALCOHOLS AND ALIPHATIC ETHER ALCOHOLS AND WATER DISPERSED IN SAID SOLVENT, SAID LIQUID CHLORINATED HYDROCARBON SOLVENT BEING IN PREPONDERATE PROPORTION, AND SAID WATER BEING IN THE RANGE OF ABOUT 1% TO ABOUT 20% BY WEIGHT OF SAID THIXOTROPIC PAINT REMOVER, AND SAID DISPERSION BEING THIXOTROPIC SO THAT ON AGITATION SAID MIXTURE IS A FLUID AND WHEN AT REST IS A GEL HAVING THE PROPERTY OF ADHERING TO PAINTED SURFACES WITHPUT SUBSTANTIAL RUNNING AND DISPERSIBLE IN WATER SO THAT IT MAY BE WASHED FROM A SURFACE TO WHICH IT IS APPLIED. 